OFFSET
1,2
EXAMPLE
Some solutions for n=3
..0..1..0....0..0..1....0..1..2....0..1..0....0..1..0....0..0..1....0..1..2
..1..2..0....2..2..0....2..0..1....2..0..2....1..0..1....1..2..2....0..2..1
..0..1..0....0..1..1....1..0..1....1..1..0....0..2..2....0..0..0....1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 19 2013
STATUS
approved